Method for allocating resources in wireless communication system supporting full duplex radio (fdr) technology, and apparatus therefor

ABSTRACT

A method for allocating, by a base station, resources in a wireless communication system supporting a full duplex radio (FDR) technology, according to the present invention, may comprise the steps of: receiving, from a first terminal, a buffer status report (BSR) including an indicator which indicates the urgency of uplink data transmission; and determining, on the basis of the indicator, whether to allocate an uplink sub-frame for the first terminal in a situation where a downlink sub-frame is allocated to a second terminal during a specific time interval.

TECHNICAL FIELD

The present invention relates to a wireless communication system, andmore particularly, to a method for allocating resources in a wirelesscommunication system supporting a full duplex radio (FDR) scheme andapparatus therefor.

BACKGROUND ART

A full duplex radio (FDR) or full duplex communication scheme means acommunication scheme for enabling a user equipment to simultaneouslyperform transmission and reception using the same resource. In thiscase, the same resource means the same time and frequency. FDRcommunication or full duplex communication can be referred to as two-waycommunication.

FIG. 1 is a conceptual diagram illustrating a user equipment (UE) and abase station (BS) that support FDR.

Referring to FIG. 1, there are three types of interferences in a networkthat supports the FDR. The first one is intra-device self-interference.The intra-device self-interference means that a signal transmitted froma transmit (Tx) antenna of a BS or UE is received by a receive (Rx)antenna of the BS or UE, thereby acting as interference. Since thesignal transmitted from the TX antenna is transmitted with high powerand a distance between the TX antenna and the RX antenna is relativelyshort, the signal is received at the RX antenna with almost no powerloss. Thus, receive power of the signal is much higher than that of adesired signal. The second one is UE-to-UE inter-link interference. Whena network supports the FDR, the UE-to-UE inter-link interference isincreased. Specifically, if an uplink signal transmitted by a UE isreceived by an adjacently located UE, the uplink signal may act asinterference to the adjacently located UE. This type of interference isreferred to as the UE-to-UE inter-link interference. The third one isBS-to-BS inter-link interference. Similar to the UE-to-UE inter-linkinterference, the BS-to-BS inter-link interference is also increasedwhen a network supports the FDR. If signals transmitted between BSs orheterogeneous BSs (e.g., pico, femto, relay, etc.) in a HetNet situationare received by an RX antenna of another BS, the signals may act asinterference to another BS. This type of interference is referred to asthe BS-to-BS inter-link interference.

DISCLOSURE OF THE INVENTION Technical Task

An object of the present invention is to provide a method performed by abase station for allocating resources in a wireless communication systemsupporting a full duplex radio (FDR) scheme.

Another object of the present invention is to provide a base station forallocating resources in a wireless communication system supporting afull duplex radio (FDR) scheme.

It will be appreciated by persons skilled in the art that the objectsthat could be achieved with the present invention are not limited towhat has been particularly described hereinabove and the above and otherobjects that the present invention could achieve will be more clearlyunderstood from the following detailed description.

Technical Solutions

To achieve these objects and other advantages and in accordance with thepurpose of the invention, in an aspect of the present invention,provided herein is a method for allocating resources by a base station(BS) in a wireless communication system supporting a full duplex radio(FDR) scheme, including: receiving a buffer status report (BSR)including an indicator indicating uplink data transmission urgency froma first user equipment (UE); and determining whether to allocate anuplink subframe for the first UE based on the indicator in a state inwhich a downlink subframe is allocated to a second UE in a specific timeinterval.

When the uplink data transmission urgency indicated by the indicator isequal to or higher than a predetermined threshold, the method mayfurther include allocating the uplink subframe to the first UE in thespecific time interval. When the uplink data transmission urgencyindicated by the indicator is lower than a predetermined threshold, themethod may further include determining whether to allocate the uplinksubframe to the first UE in the specific time interval based on feedbackinformation received from the second UE. When the feedback informationreceived from the second UE includes an indicator indicating acceptanceof the allocation of the uplink subframe to the first UE in the specifictime interval, the method may further include allocating the uplinksubframe to the first UE in the specific time interval. When thefeedback information received from the second UE includes an indicatorindicating rejection of the allocation of the uplink subframe to thefirst UE in the specific time interval, the method may further includeallocating a resource different from the downlink subframe allocated tothe second UE to the first UE. The different resource may be a timeresource or a frequency resource different from the downlink subframeallocated to the second UE.

When the feedback information received from the second UE includes anindicator indicating rejection of the allocation of the uplink subframeto the first UE in the specific time interval, the method may furtherinclude transmitting, to the first UE, a message instructing to hold offuplink transmission during the specific time interval.

The method may further include: receiving, from the second UE, a Qualityof Service (QoS) level required by the second UE; and when the QoS levelis equal to or higher than a predetermined threshold, allocating theuplink subframe to the first UE on a frequency band different from thatof the downlink subframe allocated to the second UE in the specific timeinterval.

The method may further include: receiving, from the second UE, a Qualityof Service (QoS) level required by the second UE; and when the QoS levelis equal to or higher than a predetermined threshold, allocating adownlink subframe for the second UE on a frequency band different fromthat of the downlink subframe allocated to the second UE in the specifictime interval.

In another technical aspect of the present invention, provided herein isa base station (BS) for allocating resources in a wireless communicationsystem supporting a full duplex radio (FDR) scheme, including: areceiver configured to receive a buffer status report (BSR) including anindicator indicating uplink data transmission urgency from a first userequipment (UE); and a processor configured to determine whether toallocate an uplink subframe for the first UE based on the indicator in astate in which a downlink subframe is allocated to a second UE in aspecific time interval.

When the uplink data transmission urgency indicated by the indicator isequal to or higher than a predetermined threshold, the processor may beconfigured to allocate the uplink subframe to the first UE in thespecific time interval. When the uplink data transmission urgencyindicated by the indicator is lower than a predetermined threshold, theprocessor may be configured to determine whether to allocate the uplinksubframe to the first UE in the specific time interval based on feedbackinformation received from the second UE. When the feedback informationreceived from the second UE includes an indicator indicating acceptanceof the allocation of the uplink subframe to the first UE in the specifictime interval, the processor may be configured to allocate the uplinksubframe to the first UE in the specific time interval.

When the feedback information received from the second UE includes anindicator indicating rejection of the allocation of the uplink subframeto the first UE in the specific time interval, the processor may beconfigured to allocate a resource different from the downlink subframeallocated to the second UE to the first UE.

When the feedback information received from the second UE includes anindicator indicating rejection of the allocation of the uplink subframeto the first UE in the specific time interval, the BS may furtherinclude a transmitter configured to transmit, to the first UE, a messageinstructing to hold off uplink transmission during the specific timeinterval.

The received may be configured to further receive, from the second UE, aQuality of Service (QoS) level required by the second UE. When the QoSlevel is equal to or higher than a predetermined threshold, theprocessor may be configured to allocate the uplink subframe to the firstUE on a frequency band different from that of the downlink subframeallocated to the second UE in the specific time interval.

The received may be configured to further receive, from the second UE, aQuality of Service (QoS) level required by the second UE. When the QoSlevel is equal to or higher than a predetermined threshold, theprocessor may be configured to allocate a downlink subframe for thesecond UE on a frequency band different from that of the downlinksubframe allocated to the second UE in the specific time interval.

Advantageoud Effects

According to the present invention, communication system performance canbe improved by allocating resources in consideration of the amount,urgency, and IDI of data that will be transmitted and received between abase station and a user equipment in the system supporting full-duplexradio (communication) on the same resource.

It will be appreciated by persons skilled in the art that the effectsthat can be achieved through the present invention are not limited towhat has been particularly described hereinabove and other advantages ofthe present invention will be more clearly understood from the followingdetailed description.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a conceptual diagram illustrating a user equipment (UE) and abase station (BS) that support FDR.

FIG. 2 is a block diagram illustrating configurations of a BS 105 and aUE 110 in a wireless communication system 100.

FIG. 3 is a diagram for explaining the concept of UE-to-UE interference(or inter-device interference (IDI)).

FIG. 4 is a diagram illustrating examples of frequency division multipleaccess (FDMA) and time division multiple access (TDMA) operations when aBS operates in a full duplex (FD) mode on the same resource and UEsperforms multiple access.

FIG. 5 is a diagram illustrating a BSR data structure of the 3GPP LTEsystem. Specifically, FIG. 5(a) shows a short BSR MAC CE structure andFIG. 5(b) shows a long BSR MAC CE structure.

FIG. 6 is a diagram for explaining embodiment 1 of the presentinvention.

BEST MODE FOR INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. In the following detailed description of the inventionincludes details to help the full understanding of the presentinvention. Yet, it is apparent to those skilled in the art that thepresent invention can be implemented without these details. Forinstance, although the following descriptions are made in detail on theassumption that a mobile communication system includes 3GPP LTE system,the following descriptions are applicable to other random mobilecommunication systems in a manner of excluding unique features of the3GPP LTE.

Occasionally, to prevent the present invention from getting vaguer,structures and/or devices known to the public are skipped or can berepresented as block diagrams centering on the core functions of thestructures and/or devices. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

Besides, in the following description, assume that a terminal is acommon name of such a mobile or fixed user stage device as a userequipment (UE), a mobile station (MS), an advanced mobile station (AMS)and the like. And, assume that a base station (BS) is a common name ofsuch a random node of a network stage communicating with a terminal as aNode B (NB), an eNode B (eNB), an access point (AP) and the like.Although the present specification is described based on IEEE 802.16msystem, contents of the present invention may be applicable to variouskinds of other communication systems.

In a mobile communication system, a user equipment is able to receiveinformation in downlink and is able to transmit information in uplink aswell. Information transmitted or received by the user equipment node mayinclude various kinds of data and control information. In accordancewith types and usages of the information transmitted or received by theuser equipment, various physical channels may exist.

The following descriptions are usable for various wireless accesssystems including CDMA (code division multiple access), FDMA (frequencydivision multiple access), TDMA (time division multiple access), OFDMA(orthogonal frequency division multiple access), SC-FDMA (single carrierfrequency division multiple access) and the like. CDMA can beimplemented by such a radio technology as UTRA (universal terrestrialradio access), CDMA 2000 and the like. TDMA can be implemented with sucha radio technology as GSM/GPRS/EDGE (Global System for Mobilecommunications)/General Packet Radio Service/Enhanced Data Rates for GSMEvolution). OFDMA can be implemented with such a radio technology asIEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, E-UTRA (EvolvedUTRA), etc. UTRA is a part of UMTS (Universal Mobile TelecommunicationsSystem). 3GPP (3rd Generation Partnership Project) LTE (long termevolution) is a part of E-UMTS (Evolved UMTS) that uses E-UTRA. The 3GPPLTE employs OFDMA in DL and SC-FDMA in UL. And, LTE-A (LTE-Advanced) isan evolved version of 3GPP LTE.

Moreover, in the following description, specific terminologies areprovided to help the understanding of the present invention. And, theuse of the specific terminology can be modified into another form withinthe scope of the technical idea of the present invention.

FIG. 2 is a block diagram for configurations of a base station 105 and auser equipment 110 in a wireless communication system 100.

Although one base station 105 and one user equipment 110 (D2D userequipment included) are shown in the drawing to schematically representa wireless communication system 100, the wireless communication system100 may include at least one base station and/or at least one userequipment.

Referring to FIG. 2, a base station 105 may include a transmitted (Tx)data processor 115, a symbol modulator 120, a transmitter 125, atransceiving antenna 130, a processor 180, a memory 185, a receiver 190,a symbol demodulator 195 and a received data processor 197. And, a userequipment 110 may include a transmitted (Tx) data processor 165, asymbol modulator 170, a transmitter 175, a transceiving antenna 135, aprocessor 155, a memory 160, a receiver 140, a symbol demodulator 155and a received data processor 150. Although the base station/userequipment 105/110 includes one antenna 130/135 in the drawing, each ofthe base station 105 and the user equipment 110 includes a plurality ofantennas. Therefore, each of the base station 105 and the user equipment110 of the present invention supports an MIMO (multiple input multipleoutput) system. And, the base station 105 according to the presentinvention may support both SU-MIMO (single user-MIMO) and MU-MIMO (multiuser-MIMO) systems.

In downlink, the transmitted data processor 115 receives traffic data,codes the received traffic data by formatting the received traffic data,interleaves the coded traffic data, modulates (or symbol maps) theinterleaved data, and then provides modulated symbols (data symbols).The symbol modulator 120 provides a stream of symbols by receiving andprocessing the data symbols and pilot symbols.

The symbol modulator 120 multiplexes the data and pilot symbols togetherand then transmits the multiplexed symbols to the transmitter 125. Indoing so, each of the transmitted symbols may include the data symbol,the pilot symbol or a signal value of zero. In each symbol duration,pilot symbols may be contiguously transmitted. In doing so, the pilotsymbols may include symbols of frequency division multiplexing (FDM),orthogonal frequency division multiplexing (OFDM), or code divisionmultiplexing (CDM).

The transmitter 125 receives the stream of the symbols, converts thereceived stream to at least one or more analog signals, additionallyadjusts the analog signals (e.g., amplification, filtering, frequencyupconverting), and then generates a downlink signal suitable for atransmission on a radio channel. Subsequently, the downlink signal istransmitted to the user equipment via the antenna 130.

In the configuration of the user equipment 110, the receiving antenna135 receives the downlink signal from the base station and then providesthe received signal to the receiver 140. The receiver 140 adjusts thereceived signal (e.g., filtering, amplification and frequencydownconverting), digitizes the adjusted signal, and then obtainssamples. The symbol demodulator 145 demodulates the received pilotsymbols and then provides them to the processor 155 for channelestimation.

The symbol demodulator 145 receives a frequency response estimated valuefor downlink from the processor 155, performs data demodulation on thereceived data symbols, obtains data symbol estimated values (i.e.,estimated values of the transmitted data symbols), and then provides thedata symbols estimated values to the received (Rx) data processor 150.The received data processor 150 reconstructs the transmitted trafficdata by performing demodulation (i.e., symbol demapping, deinterleavingand decoding) on the data symbol estimated values.

The processing by the symbol demodulator 145 and the processing by thereceived data processor 150 are complementary to the processing by thesymbol modulator 120 and the processing by the transmitted dataprocessor 115 in the base station 105, respectively.

In the user equipment 110 in uplink, the transmitted data processor 165processes the traffic data and then provides data symbols. The symbolmodulator 170 receives the data symbols, multiplexes the received datasymbols, performs modulation on the multiplexed symbols, and thenprovides a stream of the symbols to the transmitter 175. The transmitter175 receives the stream of the symbols, processes the received stream,and generates an uplink signal. This uplink signal is then transmittedto the base station 105 via the antenna 135.

In the base station 105, the uplink signal is received from the userequipment 110 via the antenna 130. The receiver 190 processes thereceived uplink signal and then obtains samples. Subsequently, thesymbol demodulator 195 processes the samples and then provides pilotsymbols received in uplink and a data symbol estimated value. Thereceived data processor 197 processes the data symbol estimated valueand then reconstructs the traffic data transmitted from the userequipment 110.

The processor 155/180 of the user equipment/base station 110/105 directsoperations (e.g., control, adjustment, management, etc.) of the userequipment/base station 110/105. The processor 155/180 may be connectedto the memory unit 160/185 configured to store program codes and data.The memory 160/185 is connected to the processor 155/180 to storeoperating systems, applications and general files.

The processor 155/180 may be called one of a controller, amicrocontroller, a microprocessor, a microcomputer and the like. And,the processor 155/180 may be implemented using hardware, firmware,software and/or any combinations thereof. In the implementation byhardware, the processor 155/180 may be provided with such a deviceconfigured to implement the present invention as ASICs (applicationspecific integrated circuits), DSPs (digital signal processors), DSPDs(digital signal processing devices), PLDs (programmable logic devices),FPGAs (field programmable gate arrays), and the like.

Meanwhile, in case of implementing the embodiments of the presentinvention using firmware or software, the firmware or software may beconfigured to include modules, procedures, and/or functions forperforming the above-explained functions or operations of the presentinvention. And, the firmware or software configured to implement thepresent invention is loaded in the processor 155/180 or saved in thememory 160/185 to be driven by the processor 155/180.

Layers of a radio protocol between a user equipment/base station and awireless communication system (network) may be classified into 1st layerL1, 2nd layer L2 and 3rd layer L3 based on 3 lower layers of OSI (opensystem interconnection) model well known to communication systems. Aphysical layer belongs to the 1st layer and provides an informationtransfer service via a physical channel. RRC (radio resource control)layer belongs to the 3rd layer and provides control radio resourcedbetween UE and network. A user equipment and a base station may be ableto exchange RRC messages with each other through a wirelesscommunication network and RRC layers.

In the present specification, although the processor 155/180 of the userequipment/base station performs an operation of processing signals anddata except a function for the user equipment/base station 110/105 toreceive or transmit a signal, for clarity, the processors 155 and 180will not be mentioned in the following description specifically. In thefollowing description, the processor 155/180 can be regarded asperforming a series of operations such as a data processing and the likeexcept a function of receiving or transmitting a signal without beingspecially mentioned.

FIG. 3 is a diagram for explaining the concept of UE-to-UE interference(or IDI).

The IDI occurs only in the FDR system because the same resource is usedwithin a cell. Specifically, FIG. 3 shows the concepts of the IDI, whichoccurs when a BS uses an FD mode (i.e., a mode for simultaneouslyperforming transmission and reception using the same frequency) on thesame resource. Although FIG. 3 shows a simple example in which there aretwo UEs for convenience of description, the present invention is notlimited to the number of UEs. In the legacy full-duplex communicationsystem, since frequency division duplex (FDD) or time division duplex(TDD) is used, i.e., resources used for transmission are different fromthose used for reception, the IDI does not occur. However, interferencebetween neighboring cells in the legacy system still causes a problem tothe FDR system. That is, in the FDR system, there is not only fullduplex where the same resource is used but also full duplex wheredifferent resources are used.

FIG. 4 is a diagram illustrating examples of frequency division multipleaccess (FDMA) and time division multiple access (TDMA) operations when aBS operates in a full duplex (FD) mode on the same resource and UEsperforms multiple access.

In the TDD system using full-duplex communication on the same resource,there are frame configurations for measuring interference betweenunsynchronized UEs and configuration methods for attempting to transmitand receive signals for identification between UEs. In addition, it ispossible to achieve simultaneous transmission and reception using aUE-specific configuration for allocating different configurations toindividual UEs in each cell. To mitigate or cancel IDI after IDImeasurement, a unique signature can be assigned to each UE or each UEgroup. In this case, a signal for measuring interference from each UE isreferred to as a signature signal.

After receiving the signature signal, a UE can obtain signal strength ofa IDI-causing UE, a UE or signature index, a channel vector such as aphase, timing information and the like. Moreover, the signature signalcan be implemented in various forms that can be used for identifying aUE or UE group such as a code sequence, a puncturing pattern, and thelike. Unique scrambling or interleaving for a UE or UE group can beapplied using the code sequence. To facilitate interference measurementat a receiving UE, the signature signal can be exclusively transmittedby only a single UE or UE group. In this case, a minimum exclusive unitmay correspond to an orthogonal frequency division multiplex (OFDM)symbol.

In addition, in the FDR system, there may be a UE group classification(grouping) method and an IDI measurement and reporting method forgrouping. That is, UE groups may be classified using order of themagnitudes of IDI measured by individual UEs. Additionally, it ispossible to apply a UE group classification method where IDIcancellation/mitigation capability of each UE is considered instead ofthe number of UEs sharing the same resources.

Next, a description will be given of a buffer status report (BSR)performed at the medium access control (MAC) layer of the 3GPP LTEsystem. In the LTE system, a BS should know the type and amount of datato be transmitted by each UE in uplink for efficient use of uplink radioresources. To this end, a UE can transmit information on uplink data tobe transmitted by itself to the BS, and the BS can allocate uplinkresources to the corresponding UE based on the information. In thiscase, the information on the uplink data transmitted by the UE to the BScorresponds to the amount of data stored in a buffer of the UE, and thiscan be referred to as a buffer status report (BSR).

A UE transmits the BSR in the form of a MAC control element (CE), and inthe LTE system, there are two types of BSRs: a short BSR and a long BSR.

FIG. 5 is a diagram illustrating a BSR data structure of the 3GPP LTEsystem. Specifically, FIG. 5(a) shows a short BSR MAC CE structure andFIG. 5(b) shows a long BSR MAC CE structure.

Which one of the short BSR and long BSR will be selected by a UE fortransmission is determined based on the number of logical channel groups(LCGs) where uplink data exists. That is, if data to be transmitted ispresent in a single LCG, the UE transmits the short BSR to the BS. Onthe contrary, if data to be transmitted is present in two or more LCGs,the UE transmits the long BSR to the BS. In this case, the LCG means agroup of logical channels with similar Quality of Service (QoS), whichis obtained by performing grouping on multiple logical channels. FourLCGs from LCG ID #0 to LCG ID #3 have been used in the LTE system. Whenthe BS configures one radio bearer (RB) for the UE, the BS informs whichLCG logical channels of the corresponding RB belong to.

In addition, in the case of the short BSR, an identifier of an LCG,i.e., an LCG ID is included to indicate which LCG a buffer size fieldfor indicating a buffer size is for. However, in the case of the longBSR, all LCGs from an LCG with LCG ID #0 to an LCG with LCG ID #3sequentially include buffer size fields with no LCG ID.

Based on the BSR received from the UE, the BS determines resourceallocation for the corresponding UE.

When a traffic model is a full buffer or when a UL/DL subframe isdetermined at a specific time, IDI may occur. However, in the realsystem, since a UL subframe is allocated based on the BSR, an FTP modelcan be applied. In this case, a method for avoiding or cancelling IDIthat occurs fluidly is needed.

The present invention proposes a method for changing resources in asystem using full-duplex communication on the same resource byconsidering IDI effects changed according to UL/DL configurations.

As described above, the BS can allocate a UL subframe based on the BSRreceived from the UE. However, if a DL subframe is allocated to the UEat the corresponding time, the UE may be affected by IDI due to the ULsubframe. Since the BS knows DL/UL configurations of UEs, the BS canlimit UL subframe allocation by considering the minimization of the IDIeffects (including an IDI cancellation scheme).

Hereinafter, various embodiments in which the BS configures resourceallocation in consideration of IDI will be described. These variousembodiments can be implemented independently, or some of the embodimentscan be combined with each other.

Embodiment 1: Use of Resource Allocation Timer

FIG. 6 is a diagram for explaining embodiment 1 of the presentinvention.

A BS can periodically allocate DL/UL subframes to a UE using a resourceallocation timer, and this may be suitable for non-urgent data. That is,the BS may inform UE1 which will be or has been allocated a DL subframeon a specific resource (e.g., time-frequency resource) of information onUE2 which will be or has been allocated a UL subframe on the sameresource as the specific resource through high layer signaling, aphysical downlink shared channel (PDSCH), and the like [S610]. Inaddition, UE2 is scheduled to be allocated a UL subframe on the sameresource as that of the DL subframe which will be or has been allocatedto UE1 by the BS.

Thereafter, UE 1 can measure IDI from UE2, which will be or has beenallocated the UL subframe, using the information on UE2 received fromthe BS and then determine whether there is an effect of the IDI andwhether the IDI can be cancelled, using the measured IDI information[S620]. In addition, UE1 can transmit, to the BS, feedback informationincluding whether the IDI effect is present and whether the IDI can becancelled [S630].

The feedback information may include the following items. For example,as 1-bit feedback information, when the feedback information is set to‘0’, it may indicate that UE 1 rejects the allocation of the UL subframeto UE 2. When the feedback information is set to ‘1’, it may indicatethat UE 1 accepts the allocation of the UL subframe to UE 2. As anotherexample, the feedback information may be configured to have a lengthequal to or greater than 2 bits. In this case, the feedback informationmay simultaneously inform acceptance/rejection of allocation of ULsubframes to a plurality of UEs.

The BS can determine whether to allocate a UL resource to UE 2 using thefeedback information received from UE 1 [S640]. Meanwhile, the BS mayallocate the UL resource (e.g., UL subframe) to UE 2 irrespective of thefeedback information about acceptance/rejection. Alternatively, when thefeedback information indicates the rejection, the BS may allocate adifferent UL resource to UE 2 (i.e., UL UE) or instruct UE 2 to hold offthe use of the corresponding resource [S650].

In the case of periodic DL/UL allocation, it is possible to use it as afunction similar to the configuration for DL/UL UEs. A configurationperiod for each UE may be changed depending on characteristics oftransmission data. In addition, although not shown in FIG. 6, theprocedures described with reference to FIG. 6 may be performed after theBS receives BSRs from UEs.

Embodiment 2: Resource Allocation in Consideration of Urgency of Data

The resource allocation can be performed in consideration ofrequirements of transmission data. To this end, a UE can include anindicator (e.g., 1-bit indicator) indicating transmission urgency of ULdata in a BSR and then transmit the BSR to a BS. For example, when the1-bit indicator is set to ‘1’, it may indicate that the transmissionurgency of the UL data is equal to or higher than a predeterminedthreshold. Based on the indicator set to ‘1’, the BS can allocate a ULsubframe to the UE that transmits the indicator without consideration ofIDI at a victim UE (here, the victim UE means a UE that receivesinterference from a UE which transmits a UL signal in a time intervalwhere a DL subframe is allocated). On the contrary, when the indicatoris set to ‘0’ (that is, the urgency of the data is lower than thepredetermined threshold), the procedures described with reference toFIG. 6 can be performed in the same manner.

As another example, the indicator may be configured to have a size of 2bits or more to indicate a level of transmission urgency of UL data. TheBS may allocate resources by giving a higher priority to data withhigher urgency through comparison of transmission urgency of DL data andthe level of the transmission urgency of the data indicated by theindictor. In this case, the urgency may be represented as an index valuein accordance with the urgency level (for example, it is assumed thatthe urgency increases as the index value decreases). When at least oneDL subframe and at least one UL subframe are present, the BS mayallocate either the DL subframe(s) or the UL subframe(s) at a specifictime by determining the urgency in consideration of the IDI effect. Forexample, assuming that DL data transmission urgency of DL UE 1 is ‘3’,and UL data transmission urgency of UL UE 1 and UL data transmissionurgency of UL UE 2 is ‘1’ respectively, the BS may allocate UL subframesonly at a specific time by considering that the DL UE is damaged due tothe IDI. In this case, the BS may request victim candidate UEs totransmit feedback on acceptance/rejection in advance as shown in FIG. 6.

Embodiment 3: Resource Allocation in Consideration of Requirements ofTransmission Data

A BS can limit UL subframe allocation to satisfy requirements of avictim UE in consideration of QoS required by the victim UE, and thevictim UE can inform the BS of its required QoS level through, forexample, a 1-bit indicator. For example, if the 1-bit indicator is setto ‘1’, it may indicate that the victim UE requires a service equal toor greater than a predetermined QoS value. As another example, therequired QoS level may be indicated through an indicator with a size of2 bits or more. In this case, the required QoS level may be representedas an index value in accordance with the required level. In other words,the BS can limit the UL subframe allocation in consideration of thecorresponding required QoS level.

As described above, the BS can simultaneously consider the UL datatransmission urgency and the QoS level required by the victim UE. Whenboth of the QoS and the urgency needs to be satisfied, the BS may changea frequency allocated to a DL UE or UL UE and then allocate a DLsubframe to the DL UE or a UL subframe to the UL UE in the changedfrequency band.

Embodiment 4: Resource Allocation in Consideration of NACK

A BS can allocate resources in consideration of a NACK signal. In thecase of a victim UE, the BS can limit UL subframe allocation accordingto the number of NACK signals in response to DL data which are generatedby the victim UE. In the case of an aggressor UE (here, the aggressor UEmeans a UE allocated a UL subframe which causes interference to a victimUE allocated a DL subframe in the same time interval), the BS can limitDL subframe allocation according to the number of generated NACK signalsin response to UL data. In this case, requirements for transmission datamay be simultaneously considered.

Regarding available frequency resources, the BS may allocate theresources by considering the number of UEs that will be allocated ULsubframes. Alternatively, the BS may allocate the resource byconsidering not only the number of UEs that will be allocated ULsubframes but also the degree of IDI effects. For example, whenfrequencies f1, f2, and f3 are used on the assumption that the IDIeffects are the same, the BS may allocate other frequencies (i.e., f2 orf3) except f1 to some UEs if the number of UL subframes allocated in f1increases in a specific time interval.

When a packet loss is not allowed as in a TCP data channel, feedback onQoS is not used. In addition, in this case, the BS may give a higherpriority to TCP data. In the case of TCP DL data, the BS may limitresource allocation for other UL UEs in consideration of IDI. Moreover,regarding ACK/NACK signals in response to corresponding DL data, the BSmay allocate resources to other DL UEs at the corresponding time.

The BS may allocate UL/DL UEs as evenly as possible with respect to eachfrequency resource by considering a situation in which a high trafficfluctuation occurs. The BS allocates resources to individual UEs in theFDR system as evenly as possible in consideration of BSRs by managing nfrequency candidate resources (where n<N, N is the total number of FDRfrequencies). In this case, if a frequency is not allocated to a randomUE with respect to the n candidates, the BS may operate as if the BSreceives NACK from the corresponding UE. Alternatively, the BS mayinitiate a timer operation for the corresponding UE.

If such resource allocation methods are performed based on grouping, itis possible to obtain an advantage that the resource allocation can beeasily performed using measured IDI-related information. For example,considering that best grouping is to allocate resources between UEs in acorresponding group based on the amount of measured IDI, and in thiscase, IDI effects on a victim UE are small, it is possible to neglectthe IDI effects on the victim UE.

The above-described embodiments may correspond to combinations ofelements and features of the present invention in prescribed forms. And,it may be able to consider that the respective elements or features maybe selective unless they are explicitly mentioned. Each of the elementsor features may be implemented in a form failing to be combined withother elements or features. Moreover, it may be able to implement anembodiment of the present invention by combining elements and/orfeatures together in part. A sequence of operations explained for eachembodiment of the present invention may be modified. Some configurationsor features of one embodiment may be included in another embodiment orcan be substituted for corresponding configurations or features ofanother embodiment. And, it is apparently understandable that a newembodiment may be configured by combining claims failing to haverelation of explicit citation in the appended claims together or may beincluded as new claims by amendment after filing an application.

It will be apparent to those skilled in the art that the presentinvention can be embodied in other specific forms without departing fromthe spirit and essential characteristics of the invention. Thus, theabove embodiments are to be considered in all respects as illustrativeand not restrictive. The scope of the invention should be determined byreasonable interpretation of the appended claims and all change whichcomes within the equivalent scope of the invention are included in thescope of the invention.

INDUSTRIAL APPLICABILITY

A method for allocating resources in a wireless communication systemsupporting a full duplex radio (FDR) scheme and apparatus therefor canbe applied industrially.

What is claimed is:
 1. A method for allocating resources by a basestation (BS) in a wireless communication system supporting a full duplexradio (FDR) scheme, the method comprising: receiving a buffer statusreport (BSR) including an indicator indicating uplink data transmissionurgency from a first user equipment (UE); and determining whether toallocate an uplink subframe for the first UE based on the indicator in astate in which a downlink subframe is allocated to a second UE in aspecific time interval.
 2. The method of claim 1, further comprising:when the uplink data transmission urgency indicated by the indicator isequal to or higher than a predetermined threshold, allocating the uplinksubframe to the first UE in the specific time interval.
 3. The method ofclaim 1, further comprising: when the uplink data transmission urgencyindicated by the indicator is lower than a predetermined threshold,determining whether to allocate the uplink subframe to the first UE inthe specific time interval based on feedback information received fromthe second UE.
 4. The method of claim 3, further comprising: when thefeedback information received from the second UE includes an indicatorindicating acceptance of the allocation of the uplink subframe to thefirst UE in the specific time interval, allocating the uplink subframeto the first UE in the specific time interval.
 5. The method of claim 3,further comprising, when the feedback information received from thesecond UE includes an indicator indicating rejection of the allocationof the uplink subframe to the first UE in the specific time interval,allocating a resource different from the downlink subframe allocated tothe second UE to the first UE.
 6. The method of claim 3, furthercomprising: when the feedback information received from the second UEincludes an indicator indicating rejection of the allocation of theuplink subframe to the first UE in the specific time interval,transmitting, to the first UE, a message instructing to hold off uplinktransmission during the specific time interval.
 7. The method of claim5, wherein the different resource comprises a time resource or afrequency resource different from the downlink subframe allocated to thesecond UE.
 8. The method of claim 1, further comprising: receiving, fromthe second UE, a Quality of Service (QoS) level required by the secondUE; and when the QoS level is equal to or higher than a predeterminedthreshold, allocating the uplink subframe to the first UE on a frequencyband different from that of the downlink subframe allocated to thesecond UE in the specific time interval.
 9. The method of claim 1,further comprising: receiving, from the second UE, a Quality of Service(QoS) level required by the second UE; and when the QoS level is equalto or higher than a predetermined threshold, allocating a downlinksubframe for the second UE on a frequency band different from that ofthe downlink subframe allocated to the second UE in the specific timeinterval.
 10. A base station (BS) for allocating resources in a wirelesscommunication system supporting a full duplex radio (FDR) scheme, the BScomprising: a receiver configured to receive a buffer status report(BSR) including an indicator indicating uplink data transmission urgencyfrom a first user equipment (UE); and a processor configured todetermine whether to allocate an uplink subframe for the first UE basedon the indicator in a state in which a downlink subframe is allocated toa second UE in a specific time interval.
 11. The BS of claim 10, whereinwhen the uplink data transmission urgency indicated by the indicator isequal to or higher than a predetermined threshold, the processor isconfigured to allocate the uplink subframe to the first UE in thespecific time interval.
 12. The BS of claim 10, wherein when the uplinkdata transmission urgency indicated by the indicator is lower than apredetermined threshold, the processor is configured to determinewhether to allocate the uplink subframe to the first UE in the specifictime interval based on feedback information received from the second UE.13. The BS of claim 12, wherein when the feedback information receivedfrom the second UE includes an indicator indicating acceptance of theallocation of the uplink subframe to the first UE in the specific timeinterval, the processor is configured to allocate the uplink subframe tothe first UE in the specific time interval.
 14. The BS of claim 12,wherein when the feedback information received from the second UEincludes an indicator indicating rejection of the allocation of theuplink subframe to the first UE in the specific time interval, theprocessor is configured to allocate a resource different from thedownlink subframe allocated to the second UE to the first UE.
 15. The BSof claim 12, further comprising, when the feedback information receivedfrom the second UE includes an indicator indicating rejection of theallocation of the uplink subframe to the first UE in the specific timeinterval, a transmitter configured to transmit, to the first UE, amessage instructing to hold off uplink transmission during the specifictime interval.
 16. The BS of claim 10, wherein the received isconfigured to further receive, from the second UE, a Quality of Service(QoS) level required by the second UE, and wherein when the QoS level isequal to or higher than a predetermined threshold, the processor isconfigured to allocate the uplink subframe to the first UE on afrequency band different from that of the downlink subframe allocated tothe second UE in the specific time interval.
 17. The BS of claim 10,wherein the received is configured to further receive, from the secondUE, a Quality of Service (QoS) level required by the second UE, andwherein when the QoS level is equal to or higher than a predeterminedthreshold, the processor is configured to allocate a downlink subframefor the second UE on a frequency band different from that of thedownlink subframe allocated to the second UE in the specific timeinterval.